Sustainable buildings feasible if we think outside the box
Given the recent interest in green buildings in the media, let me propose a paradigm shift. Instead of focusing on increasing the supply of energy, what if we focus on reducing demand? Every unit of energy not used results in a corresponding reduction in generation.
Can we start with ending the open-door practice of street- front shops? While cool air from these shops is refreshing to pedestrians, it carries a cost. Energy is used in the air-conditioning process. This practice began before air conditioning was invented.
How many photovoltaic panels are needed to offset this wasteful practice? It must be possible to look for changes in regulations that would encourage more energy-efficient designs. For instance, if we install paddle fans, air-conditioning homes could surely be avoided for part of the year. Ceiling fans use far less energy. They were common in buildings in the tropics before mechanical cooling was available. I wonder how many hours in a year air conditioners could stay idle if ceiling fans were installed.
In homes built under the small-house policy in the New Territories, the ceiling may be too low for ceiling fans. If the 8.2-metre maximum building height regulation were relaxed, ceiling fans could be installed to reduce energy use.
Current thinking in sustainable building design and operation involves integrated design; that is, bringing together all parties to create a building with superior performance that achieves energy reduction.
For integrated design to succeed, all parties must come together and think beyond each person's immediate circle of influence. Better solutions are inevitable with integrated design. Buildings would no longer be engineered after the basic architecture was established. Positive project outcomes may include minimised solar impact and reduced air-conditioning load, reduced power use for electric lighting, minimising the material used. A healthier indoor environment leads to increased occupant satisfaction and productivity. Solutions may include natural ventilation, daylighting and passive solar design.
We need to ask if we are ready to look beyond our own small circles and seek an improved approach to building design. By that I mean an integrated design resulting in more sustainable buildings. How much energy can we save by 2020? Far more than the 1 per cent projected for Hong Kong by installing renewable energy systems. Let us start by setting our thermostats one degree warmer.
Moses D. F. Ling, associate professor, department of architectural engineering, Penn State University, Pennsylvania, US